Antiarrhythmics After Ablation of Atrial Fibrillation - 5A Study

Description:

The goal of the trial was to evaluate empirical treatment with antiarrhythmic drug (AAD) therapy compared with no-AAD therapy among patients with paroxysmal atrial fibrillation (AF) undergoing ablation.

Hypothesis:

Empirical AAD would be more effective in preventing atrial arrhythmias after pulmonary vein isolation.

Study Design

  • Randomized
  • Parallel

Patients Screened: 475
Patients Enrolled: 110
Mean Follow Up: 6 weeks
Mean Patient Age: 56 years
Female: 30
Mean Ejection Fraction: 61%

Patient Populations:

  • Patients with paroxysmal AF undergoing pulmonary vein isolation

Exclusions:

  • Persistent AF or atrial flutter
  • Inability to tolerate any AAD therapy
  • Amiodarone within 3 months of the procedure
  • Inability to follow-up
  • Participation in another clinical trial

Primary Endpoints:

Composite of:
  • Atrial arrhythmias >24 hours in duration;
  • Atrial arrhythmias causing hospitalization, cardioversion, or initiation/change in antiarrhythmic drug therapy; and
  • Termination of antiarrhythmic drug therapy due to intolerance

Secondary Endpoints:

  • Total number of atrial arrhythmias
  • Number of atrial arrhythmia episodes other than AF
  • Number of days with any atrial arrhythmia

Drug/Procedures Used:

Patients with paroxysmal AF undergoing ablation were randomized to empirical AAD therapy for 6 weeks (n = 53) versus no-AAD therapy (n = 57).

Concomitant Medications:

Suggested AAD therapy on the basis of heart disease:
  • Propafenone or flecainide if normal left ventricular (LV) function and no coronary artery disease (CAD)
  • Sotolol if normal LV function with CAD
  • Sotolol or dofetilide if abnormal LV function

Use of AAD therapy in the AAD group:
  • Flecainide 34%
  • Propafenone 26%
  • Sotolol 36%
  • Dofetilide 4%

Principal Findings:

Overall, 110 patients were randomized. There was no difference in baseline characteristics between the groups. In the AAD group, the mean age was 56 years, 70% of participants were men, mean duration of AF was 71 months, history of previous AF ablation was 25%, and mean LV ejection fraction was 61%. In the AAD group, two-thirds of the patients were restarted on the same AAD that they were taking just prior to the procedure.

The proportion of patients that reached the primary composite endpoint was 19% in the AAD group versus 42% in the no-AAD group (p = 0.005). Arrhythmia lasting more than 24 hours or requiring initiation/change in AAD therapy was 2% versus 15% (p = 0.0012), cardioversion/hospitalization for arrhythmia was 5% versus 9% (p = 0.40), and an adverse effect from AAD therapy was 3% versus 0% (p = 0.11), respectively.

Interpretation:

Among patients with paroxysmal AF undergoing pulmonary vein isolation, 6 weeks of empirical AAD therapy post-procedure was associated with reduced incidence of clinically significant atrial arrhythmias. It is unknown if the reduction in atrial arrhythmias in the 6 weeks after an ablation procedure, referred to as the "blanking period," will translate into reduced long-term atrial arrhythmias. Adverse drug effects did not appear to be increased in the AAD group. The results of this trial do not apply to patients with persistent or permanent AF.

References:

Roux JF, Zado E, Callans DJ, et al. Antiarrhythmics after ablation of atrial fibrillation (5A study). Circulation 2009;120:1036-40.

Clinical Topics: Arrhythmias and Clinical EP, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Statins

Keywords: Pulmonary Veins, Electric Countershock, Propafenone, Phenethylamines, Sotalol, Flecainide, Catheter Ablation, Hospitalization, Sulfonamides


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